A personal wireless area network (WPAN) is a network used for communication among computing devices (for example, telephones and personal digital assistants) close to one person. The devices may or may not belong to the person in question. The reach of a WPAN may be a few meters. WPANs may be used for intrapersonal communication among the personal devices themselves, or for connecting via an uplink to a higher level network and the Internet. Personal area networks may be wired with computer buses such as a universal serial bus (USB) and FireWire.
The IEEE 802.15.3 Task Group 3c (TG3c) was formed in March 2005. TG3c is developing a millimeter-wave (mmWawe) based alternative physical layer (PHY) for the existing 802.15.3 Wireless Personal Area Network (WPAN) Standard 802.15.3-2003.
This mmWave WPAN may operate in a band including 57-64 GHz unlicensed band defined by FCC 47 CFR 15.255. The millimeter-wave WPAN may allow high coexistence, in a close physical spacing, with all other microwave systems in the 802.15 family of WPANs.
In addition, the millimeter-wave WPAN may allow very high data rate over 2 Gbit/s applications such as high speed internet access, streaming content download (e.g., video on demand, high-definition television (HDTV), home theater, etc.), real time streaming and wireless data bus for cable replacement. Optional data rates in excess of 3 Gbit/s may be provided.
However, an mmWave communication link is significantly less robust than those at lower frequencies (e.g. 2.4 GHz and 5 GHz bands) due to both oxygen absorption and high attenuation through obstructions. In addition, a mmWave communication link prefers to use directional antenna to increase the communication range, and the use of directional antenna makes a link very sensitive to mobility. For example, a slight change in the orientation of the device or the movement of a nearby object and/or person may disrupt the link. Therefore, there is a need to design a mechanism to enable fast recovery of the directional communication link with minimum service disruption.
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